Front Axle Clutch?

JcGilmour · **Posted:** Sat Jan 09, 2010 10:20 am

Is there a front axle clutch in any jeep 4WD systems?

In specific, I have a 2005 Liberty Limited with 4WDL, N, 4WDHpt and 4WDHft. I believe the front axle (differential) is in motion all the time the vehicle is moving unlike my former vehicle a GM, that when in 2WD, broke power to both front drive shaft and one half-axle thus allowing the front differential and front drive shaft to remain stationary when in 2WD saving fuel.

I see the advisories stating that shifts into 4WDH from 2 should be made at 55mph or lower. This implies that a synchronizer in the transfer case that would bring the front axle and front shaft up to speed is in play, implying that if fact, they do spin down the front axle. But, I have been under my vehicle with the wheels on the ground and in 2WD and can not trun the front axle. What ever happened to locking front hubs?

Thanks for any information.
John

JeepinJarhead03 · **Posted:** Sat Jan 09, 2010 1:31 pm

locking hubs went away with greasable ball joints and ujoints that you could get out without breaking the yoke into little pieces(kk's) and buying a new 300 dollar driveshaft

everythings in motion on ours there's just no torque being applied

InCommando · **Posted:** Sat Jan 09, 2010 1:44 pm

Yeah, lockable hubs are a victim of the people who need chain t-cases because the much stronger gear to gear units are too noisy. :roll:

The explanation that I have heard is that the much simpler ( but PITA) unit bearings and other driveline "advancements" have made it so that their is very little additional drag by not disconnecting the front driveline. The minimul fuel $ loss is made up for (supposedly) by the lower maint. required of the newer systems over the older lock-outs, which required servicing. Then again there is the ease of use factor.

JeepinJarhead03 · **Posted:** Sat Jan 09, 2010 2:01 pm

in a perfect world that's true

in a perfect world window regulators dont fail every 30k miles though lol

RED_KJ_666 · **Posted:** Sat Jan 09, 2010 11:29 pm

What I think is Crazy is that working in a truck parts warehouse I've seen Warn hub conversions for Isuzu Rodeos....... and Kia Sportages.... But people around here look at me like I'm crazy for doing up my Libby

tjkj2002 · **Posted:** Sun Jan 10, 2010 12:50 am

RED_KJ_666 wrote:

What I think is Crazy is that working in a truck parts warehouse I've seen Warn hub conversions for Isuzu Rodeos....... and Kia Sportages.... But people around here look at me like I'm crazy for doing up my Libby

Those vehicles that the kits are are for came with some sort of auto locking hubs already(take the Kia,and only available for the '95-'01's).The only kit out there that is a total swap from a non-locking type hub to one is for the D30 axles(SFA D30's only) and that will cost you a pretty penny to boot.

Albert · **Posted:** Sun Jan 10, 2010 2:05 am

RED_KJ_666 wrote:

What I think is Crazy is that working in a truck parts warehouse I've seen Warn hub conversions for Isuzu Rodeos....... and Kia Sportages.... But people around here look at me like I'm crazy for doing up my Libby

I remember the good old days. Get up in the morning....grab a cup of coffee....walk out through a foot of snow to the passenger side and click......walk over to the drivers side and click...and fire it up.... it was gonna be a 4wd day... :mrgreen:

..

...........

JeepinJarhead03 · **Posted:** Sun Jan 10, 2010 2:07 am

that or forget, make it halfway out of the driveway, get stuck and start cursin then spend 5 minutes diggin at the back only to realise the front wasn't diggin at all lol

InCommando · **Posted:** Sun Jan 10, 2010 11:18 am

Dec. 1 - Lock Hubs
Feb. 28 - Unlock Hubs

:mrgreen:

ATXKJ · **Posted:** Sun Jan 10, 2010 11:36 am

Quote:

This implies that a synchronizer in the transfer case

the implication is incorrect. The shift lever pushes against a spring which pushes against a gear - it there is any variation front to rear - tire size, tire wear, tire pressure - the lever will shift and the gear will not, the lever will be at 4wd and you will be in 2wd
(or if it shifts in - it may not shift out of 4wd) -
full time 4wd is better about this because it has a differential within the transfer case - but any mismatch will still cause hard shifting.

tommudd · **Posted:** Sun Jan 10, 2010 11:43 am

InCommando wrote:

Dec. 1 - Lock Hubs
Feb. 28 - Unlock Hubs

:mrgreen:

Yes thats about what I always did never worried about it.

Dje Ryu · **Posted:** Sun Jan 10, 2010 12:09 pm

tommudd wrote:

InCommando wrote:

Dec. 1 - Lock Hubs
Feb. 28 - Unlock Hubs

:mrgreen:

Yes thats about what I always did never worried about it.

You guys and your 4 seasons. :lol:

Around here, those dates are a bit different...

Oct 1 - Lock in hubs
Apr 30 - unlock

FreedomKJ · **Posted:** Sun Jan 10, 2010 6:50 pm

Snow? What's that?

4wd is for mud and rocks. :SOMBRERO:

JcGilmour · **Posted:** Tue Jan 12, 2010 10:43 pm

ATXKJ wrote:

Quote:

This implies that a synchronizer in the transfer case

the implication is incorrect. The shift lever pushes against a spring which pushes against a gear - it there is any variation front to rear - tire size, tire wear, tire pressure - the lever will shift and the gear will not, the lever will be at 4wd and you will be in 2wd
(or if it shifts in - it may not shift out of 4wd) -
full time 4wd is better about this because it has a differential within the transfer case - but any mismatch will still cause hard shifting.

Thanks for the information. Does the indicator text indicate correctly? "PART TIME" is it really? In other words, does the indicator display the lever position or the TC.

JeepinJarhead03 · **Posted:** Tue Jan 12, 2010 11:26 pm

i believe the indicator is dependent on position of the linkage against a mounted switch so no, no real indication either

JcGilmour · **Posted:** Mon Jan 18, 2010 5:01 pm

Because I am a cheap sob, I will look for some synthetic axle lube of low viscosity in an attempt to mitigate the parasitic losses.

Thanks to all who responded on this topic.
John

oldMountainMan · **Posted:** Fri Jan 22, 2010 5:49 am

InCommando wrote:

Dec. 1 - Lock Hubs
Feb. 28 - Unlock Hubs

:mrgreen:

In Denver it was more like:
Oct. 25, lock hubs.
May 1, Unlock hubs.

oldMountainMan · **Posted:** Fri Jan 22, 2010 6:06 am

ATXKJ wrote:

Quote:

This implies that a synchronizer in the transfer case

the implication is incorrect. The shift lever pushes against a spring which pushes against a gear - it there is any variation front to rear - tire size, tire wear, tire pressure - the lever will shift and the gear will not, the lever will be at 4wd and you will be in 2wd
(or if it shifts in - it may not shift out of 4wd) -
full time 4wd is better about this because it has a differential within the transfer case - but any mismatch will still cause hard shifting.

I had a couple of Scout II's. They did not have the spring. If you tried to take it out of 4wd while turning, or you had a tire mismatch, the lever wouldn't move. If all else failed. You could get it out by backing up.

The spring-loaded set up saves you the aggravation of not being able to move the lever, but the disadvantage is that if you do have a tire mismatch, you could be running in 4wd on paving for a long time while thinking you're in 2wd, possibly causing damage to the drive train.

JcGilmour · **Posted:** Fri Jan 22, 2010 10:23 am

"Spring linkage vs direct"

I notice that the spring linkage is not always in play. Coming out of low range for instance, is a direct connect. Yesterday I was playing in the snow and when finished, had to rock the vehicle several times before I could unload the transfer case to allow return to 2Whi

XJMA · **Posted:** Fri Jan 22, 2010 11:58 am

There is no 'clutch' for the front axle. What you have is a part time and full time transfer case.

Part time means that the front and rear driveshafts are spinning at the exact same speed, no matter what. This is only for use in snow, dirt, offroad, etc. Yo don't want to use this on dry pavement, or even rainy pavement. It will put lots of stress on the Tcase.

Full time means that there is a differential in the Tcase, so that the front and rear shafts can spin at different speeds, and so you can use full time on the pavement.

Both of these 4high modes are synchronized, so you can shift on the fly at any speed (they say under 55). Just make sure you're going straight and you're not spinning tire while trying to shift!! That is a bad thing! Stop spinning tire before you shift. Shift the lever fast.

4low is not synchronized, which is why it's good to be just barely rolling and shift it really fast as well. Being just barely rolling makes it so that the gears can mesh easily. Sometimes if you have your foot on the brake and try to shift into 4low, the gears hit each other and won't go in....which is why you should be just barely rolling if you need to shift into 4low.

There is no spring for the shifter, it's a direct linkage. If there is a delay in the engagement, you may need to adjust the linkage, it's very easy to do so, just unbolt one bolt in the linkage so it's free, manually shift the lever on the Tcase to 2, make sure the lever is in 2, then tighten it up. The linkage can go out of adjustment when the tranny and motor mounts wear, or if you bash in your Xmember!!

There are some full-time cases that have something of a clutch, but it's more like a torque converter called a viscous coupling. The 249 and some other cases that came in grand cherokees have them. Not sure if any of these cases came in KJs?? They are undesireable, IMO. The viscous coupling can wear out and is expensive to replace. IF you have a part time like a 242, it's got spider gears just like a diff, so you really can't wear that out, however, theoretically, you could get power to only one DS just like if you're only spinnign one tire with an open diff, but I've never seen it happen. Then you factor in the ESP junk and the electronic brake operated 'limited slip' features, and things get complicated. I'm a big fan of KISS, keep it simple, stupid.

Front Axle Clutch?

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